Study On The Thermochemical Energy Storage Of Calcium-magnesium Composite Pellets And The Adsorption Properties Of Molten Pure Li₄SiO₄ Based On High-temperature Carbon Capture

CaO/CaCO₃ reversible carbonation reaction（CaL）is one of the most promising candidates for high-temperature thermochemical energy storage（TCES）in concentrating solar power plants（CSP）.A carbon template method using citric acid was developed to prepare CaO high-performance heat storage materials to alleviate the deactivation phenomenon caused by the continuous carbonation-calcination cycle.The carbon template is formed by in-situ pyrolysis of citric acid during a simple heating process under nitrogen.After the second calcination in air,it has the ability to resist pore clogging and sintering,and generate Mg O stable porous nano-CaO powder,realizing long-term high-efficiency conversion rate.The citric acid is dry mixed with the limestone-dolomite mixture,and the Mg O-stabilized CaO particles are synthesized by the extrusion-spheronization method to achieve the purpose of stable and high-efficiency conversion rate.The Mg O stable CaO ball prepared by the method has high mechanical strength and can meet the requirements of practical application in a fluidized bed reactor.This simple,cost-effective and easy-to-industrial synthesis technology has great potential in CSP-TCES applications.Afterwards,the atmosphere of the thermal storage process is changed to high-purity CO₂,which forms a kind of circulation in a closed environment,which simplifies the overall structure of the system.The effect of particle size on the heat release performance of the sample was explored,and it was found that the performance of the sample with a particle size less than 0.2mm was basically the same as that of the powder sample.Lithium orthosilicate（Li₄SiO₄）is used as a potential high-temperature adsorbent for CO₂ capture and methane reforming to produce H₂ in power plants.Using a simple,cost-effective,glucose-based gentle combustion procedure,a very effective,non-doped Li₄SiO₄（MC-0.6）was synthesized.The maximum absorption capacity reaches 35.0 wt%at a low CO₂ concentration of 580°C,and this capacity can be maintained after several cycles.The characterization results show that the overall morphology is highly porous nano-agglomerates（50-100 nm）,which ensures the rapid adsorption of CO₂ on the surface.For the first time,it is found that there is a large-porous nano Li₂SiO₃ covering layer on the Li₂CO₃ molten layer.This special structure accelerates the transmission of CO₂ and the diffusion of Li⁺and O^2-through the molten layer,thereby enhancing the adsorption of CO₂.The paper has 31 pictures,8 tables,and 157 references.